This is an erotic vertical shooter game initially released for the PC98 platform in 1994. It later made its way to the PC and then the Sega Saturn. It's an adult game in which the player must battle their way through a stage before battling the stage's boss. Once the boss is defeated, the player character will then engage in sex with her in order to return the character to normal. The player is treated to an array of scenes of foreplay, molestation and even BDSM fetishes practiced within the scenes that go on between the heroes and the boss-guardians. Unlike most vertical shooter games, it uses a different system of locomotion for the players to take advantage of. For instance, both player's ships have jet boosts which quickly increases the player's ship so as to avoid tough situations and eliminates the need for speed pick-ups. Also unlike most shooters, the player's ship has a damage meter with six bars total which helps in laser- and bullet-littered screens and is a break from the standard one-hit-kills that is featured in most games of this genre. A player's health can be replenished throughout the course of the game either by retrieving engine shaped pick-ups or full-health power ups. One relatively unique (at the time) aspect to the gameplay was the addition of dialogue before and during battle between characters. When the main characters wanted to talk amongst themselves or to the bosses a picture of the interior of the character's cockpit would show up on screen either all together or one character at a time and the characters conversed with each other either to brief each other on their current location or to advance the plot. Players have a large arsenal of weaponry to choose from in the game, most of which was both common and unique to the vertical-shoot-em up. Standard firing weapons include the typical autocannon which can be fired in either full auto or semi-auto and with the right upgrades can pelt the screen in a wide spray of bullets, and the laser weapon which starts out as a long thin beam of light that can be fired at the same speed as the vulcan, but with appropriate upgrades it increases in width and strength. Along with standard firing are bombs which serve as defense against ground forces, all of which are automatically dropped once the standard weapon is fired. Players can also pick up shields which would take a certain amount of damage before being diminished by enemy fire. Side-arms can be selected which also served as ultra-bombs that changed depending on which side arm had been picked up. These include a large laser sword that can rotate the perimeter of the ship when the player ceases firing and can also guard the player's ship against enemy fire. Others include Homing Lasers, a pack of deadly bots that hunt down enemies and fire automatic lasers at them, missile launchers that fire streams of miniature missiles, and a bomb upgrade that acts as napalm fire against streams of ground forces. These side-arms can be used as ultra-bombs depending on how many the player had collected and each one is different. For instance, the laser sword enlarges so much that the blade encompasses the entire screen and the hunter bots can act as a quick rotating shield that encircles the player's ship and allows them to safely dive into enemy vehicles and cause great damage to the enemy. The game features action mixed with adult content, as well as a two-player mode. Perfect Collection is a hybrid (Windows 3.1/Mac OS) version which includes illustrations not used in PC-9801 and PC-Engine version of the game, unused music and voice in PC-Engine version in CD.